Physics is the subject that lays the base for scientific and engineering studies. Guiding students on how to score well in board examination, physics teacher Sanjay Asthana gave following tips.
Pattern change
Objective type questions will test your knowledge and thinking skills. It will also test your mathematical skills. The number of questions has increased from 27 to 37. Even two and three marks questions are going to test the comprehension skills.
Important topics
1. Electrostatics – Electric dipole system, calculation of potential energy of a system of charges, Gauss theorem and its applications, capacitor with dielectric and calculation of charge, potential, field, capacity etc.
2. Current electricity – Ohm’s law, resistance, direct and indirect measuring devices, Kirchhoff’s laws.
3. Magnetic effect of current – Moving coil galvanometer , cyclotron , applications of Ampere’s circuital law, Biot- Savart law and its applications, Lorentz force and its applications.
4. Magnetism – Domain theory of ferromagnetism, B-H curve, comparison of magnetic materials.
5. Induction and AC (alternating current) – AC generator and transformer, series LCR circuit and phasor analysis, and power in an AC circuit.
6. Solids and semiconductors – Diode and its types, V-I characteristic curves, diode as a rectifier and zener diode as a voltage regulator.
7. Photo-electric effect and duality of matter – Laws of photo-electric effect, calculation of De-Broglie wavelength, numericals covering both the topics.
8. Atoms and Nuclei – Bohr’s theory, calculation of spectral wavelengths, properties of nuclear force, binding energy graph and analysis of nuclear processes from the graph, radioactivity and numerical problems.
9. Electromagnetic waves – Displacement current, electromagnetic spectrum
10. Ray optics – Magnifying power of microscope and telescope, lens maker’s formula, single curved surface refraction, applications of TIR, numerical on lenses and mirrors.
11. Wave optics – Young’s double slit experiment, Malu’s law, Brewster’s law, single slit diffraction, Huygen’s theory and explanation of reflection and refraction from it.
How to prepare?
* Get acquainted with marks weightage, blueprint of paper.
* Five marks questions will feature from units with higher marks weightage like electrostatics, magnetic effects of current, optics and electromagnetic induction and AC.
* Stress more on application level questions.
* Pay attention to units of different variables given in numerical problem.
* Convert all units into SI system as all the formulae, which you learn in class XII are in the SI system.
* Show direction of conventional current in electrical circuits and direction of rays in ray diagrams.
* Solve sample papers of CBSE and pre-board papers not only of your school but also of other schools to know about the types of questions, which can be asked in a particular topic.
* Don’t skip steps while doing standard derivations. Every step has mark weightage.
* Don’t leave answers to numerical problems in fractions or square roots or without units. For three marks numerical, one mark is allocated for getting the correct answer with proper units.
* Draw well-labelled diagram wherever needed.
* Start writing with questions you know best.
* Comparisons should be in tabular form.
Time management
Ideally, the three hour duration paper must be attempted in 2 hours and 30 minutes. The remaining 30 minutes should be used for reviewing answers, making necessary changes, re-attempting questions you find doubtful. Also, remember to fix time for attempting short answer questions.
